Topic · topic
Inbox
Inbox is an API Evangelist index of email and inbox-oriented API platforms that developers use to send, receive, parse, route, schedule, and verify email messages. The index focuses on transactional and conversational email providers exposing programmatic access to message lifecycle, deliverability, and inbox automation primitives.
Resources
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Mailgun Email API
Mailgun provides a programmable email API for sending, receiving, tracking, and validating email at scale. Endpoints cover messages, domains, suppressions, mailing lists, webhooks, inbound routes, event streams, and inbox placement testing…
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Nylas Email API
Nylas exposes a unified REST API for email, calendar, contacts, and scheduling across Google, Microsoft, iCloud, and IMAP providers. Developers can read, send, and thread messages, manage folders and labels, handle attachments, and subscri…
Links
Providers working in Inbox
Providers whose own tags share at least two of this topic's tags, most shared first — the top 30 of 68.
| Provider | About | Rating | APIs |
|---|---|---|---|
| SMTP2GO | SMTP2GO is a New Zealand-founded email and SMS delivery platform, running since 2006, that sends and tracks transactional and marketing messages over SMTP relay or a JSON REST API from data centres in the United States, the European Union… | exemplar | 1 |
| Postmark | Postmark is an email delivery service that helps businesses send and track transactional and broadcast email reliably, replacing SMTP with a scalable service that surfaces detailed delivery analytics, bounce tracking, open and click tracki… | exemplar | 3 |
| MailerSend | MailerSend is a transactional email and SMS platform built for developers. Its v1 REST API covers email sending (single, bulk to 500 objects per request, and scheduled up to 72 hours out), SMTP relay, templates, sending domains and DNS ver… | strong | 1 |
| CommsHarbor | Transactional email and permission-based marketing infrastructure with tenant isolation, deliverability tracking, CRM, and multi-tenant governance. Self-describes as an agent-first HTTP API with a hosted MCP server. | developing | 2 |
| Customer.io | Customer.io is a customer engagement platform that combines a customer data platform, marketing automation, and messaging delivery to send behavior-triggered email, push, SMS, and in-app messages. Its API surface includes the Track API for… | exemplar | 4 |
| Brevo | Brevo (formerly Sendinblue) is a French customer-relationship platform that combines email marketing, transactional email and SMTP relay, transactional and campaign SMS, WhatsApp messaging, web and mobile push, live chat, a sales CRM, an e… | exemplar | 21 |
| Amazon SES | Amazon Simple Email Service (SES) is AWS's cloud email platform for sending and receiving mail at scale — marketing, notification and transactional. The current contract is the SES v2 API (version 2019-09-27), an 86-operation REST-JSON ser… | exemplar | 2 |
| Novu | Novu is the open-source notification infrastructure for developers. A single REST API and workflow engine route a triggered event across in-app inbox, email, SMS, push, chat (Slack / Discord / MS Teams / WhatsApp) and custom channels — wit… | exemplar | 1 |
| SendPulse | SendPulse is a multichannel marketing automation platform covering bulk email, SMTP transactional email, SMS, web push, website pop-ups, a CRM, an online course builder, and chatbots across WhatsApp, Telegram, Facebook Messenger, Instagram… | exemplar | 20 |
| Paubox | Paubox is a HIPAA compliant, HITRUST certified email infrastructure company serving healthcare organizations in the United States. Its products encrypt outbound email without recipient portals, passwords, or plugins, and work alongside Goo… | exemplar | 3 |
| AgentMail | AgentMail is an API-first email platform that gives AI agents their own email inboxes to autonomously send, receive, reply to, and act on email. Unlike traditional transactional email APIs built for one-way notifications, AgentMail is desi… | strong | 1 |
| MailPace | MailPace is a fast, privacy-focused transactional email API for developers. It delivers application email - password resets, receipts, notifications - over a simple HTTPS REST API and SMTP, with DKIM-verified sending domains, Ed25519-signe… | thin | 1 |
| Mailgun | Mailgun (by Sinch) is a transactional email API service for developers to send, receive, validate, and track emails at scale. The platform provides SMTP and HTTP APIs for sending email, inbound message routing, deliverability analytics, su… | thin | 1 |
| Mailchimp | Mailchimp is an Intuit company providing a marketing automation platform and email marketing service for managing mailing lists, creating email marketing campaigns, and automating marketing workflows. It exposes two distinct developer surf… | exemplar | 4 |
| Amazon Pinpoint | Amazon Pinpoint is a flexible and scalable outbound and inbound marketing communications service that enables you to engage with customers across multiple messaging channels including email, SMS, push notifications, and voice messages. Not… | exemplar | 2 |
| AhaSend | AhaSend is a developer-focused transactional email platform providing fast, reliable email delivery via REST API and SMTP relay. It offers features including email tracking, webhooks, email routing, suppression management, domain managemen… | exemplar | 2 |
| Infobip | Infobip is a global communications platform as a service (CPaaS) provider headquartered in Vodnjan, Croatia, and is Croatia's largest technology company. It sells programmable messaging, voice, video, email and customer engagement APIs on… | exemplar | 47 |
| Svix | Svix is an enterprise webhooks-as-a-service platform on the sending side of the webhook market. It provides a single API for delivering reliable, secure, low-latency webhooks at scale, with hosted UIs (Consumer App Portal), a polyglot SDK… | exemplar | 1 |
| Braze | Braze is a leading customer engagement platform providing REST APIs for managing user profiles, orchestrating multi-channel messaging campaigns, and exporting analytics. The platform supports email, SMS, push notifications, in-app messages… | exemplar | 1 |
| MailerLite | MailerLite is an email marketing and automation platform used by creators, e-commerce sellers and small businesses to build lists, send campaigns and run behavioural automations. The current REST API at connect.mailerlite.com exposes subsc… | exemplar | 1 |
| Nylas | Nylas connects your application to every email inbox and calendar in the world. The Nylas v3 platform provides REST APIs for email, calendar, contacts, scheduling, meeting notetaking, authentication, and administration across Google, Micro… | exemplar | 2 |
| Plunk | Plunk is an open-source (AGPL-3.0) email platform for developers that unifies transactional email, marketing campaigns, contact segmentation and event-driven workflow automation behind a single REST API. It publishes its own OpenAPI 3.1.0… | exemplar | 2 |
| Knock | Knock is notifications infrastructure as a service — a product and customer messaging platform you use to power transactional, lifecycle, broadcast, and in-product messaging across email, SMS, push, in-app, in-app guides, chat (Slack / Dis… | exemplar | 13 |
| Ortto | Ortto (formerly Autopilot) is a marketing automation, customer data platform (CDP), and analytics product. Its REST API at https://api.ap3api.com/v1 lets applications create and update people/contacts and accounts, send custom activity eve… | exemplar | 1 |
| Mailboxlayer | Real-time email validation and verification REST/JSON API operated by APILayer. Provides syntax checks, typo suggestions, MX-record lookup, SMTP verification, catch-all/role/disposable/free-provider detection, and a deliverability quality… | exemplar | 2 |
| Loops | Loops is an email platform built for software companies, combining marketing campaigns, product and lifecycle automation, and transactional email on one contact model. Its REST API v1 exposes 64 operations across contacts, contact properti… | exemplar | 1 |
| Moosend | Moosend is an email marketing and automation platform with a REST API for managing mailing lists, campaigns, subscribers, automations, and tracking email performance metrics. The API uses HTTPS with API key authentication and provides prog… | strong | 1 |
| Mailmodo | Mailmodo is an AI-powered interactive email marketing and automation platform headquartered in Bengaluru with a presence in San Francisco. It pioneered AMP-for-Email at scale, letting brands embed forms, quizzes, polls, carousels, and cale… | strong | 9 |
| Benchmark Email | Benchmark Email is an email marketing platform for small businesses, run by Benchmark Internet Group, with two live REST API generations. The current Benchmark Email API on the benchmarkemail.io platform covers contacts, contact structures… | strong | 2 |
| Zavu | Zavu is a unified multi-channel messaging platform that consolidates SMS, WhatsApp, Telegram, Email, Voice, and Messenger behind a single REST API, so developers integrate once instead of stitching together Twilio, Vonage, MessageBird and… | strong | 1 |
Tags
EmailInboxMessagingDeliverabilityTransactional Email